William Morgan Dies at 88; A Leading U.S. Astronomer

By JOHN NOBLE WILFORD

Published: June 24, 1994

William Wilson Morgan, the astronomer who discovered the spiral structure of the Milky Way galaxy, died on Tuesday at his home in Williams Bay, Wis. He was 88.

The cause of death was a heart attack, said Diana Steele, a spokeswoman for the University of Chicago. Dr. Morgan was an emeritus professor of astronomy at the university and former director of its Yerkes Observatory in Williams Bay, a town in far southern Wisconsin, near the Illinois border.

For more than 60 years a specialist in astronomical morphology -- research into the structures of stellar populations -- Dr. Morgan was considered one of the leading astronomers of this century. He devised classification systems for the brightness of stars, developed a system to determine distances to remote stars more accurately and demonstrated the existence of super-giant galaxies.

His investigations of starlight and the distances and arrangement of stars led to the discovery that gained him wide recognition in science. After years of observations and analysis, he discovered the broad pattern in which the interstellar gas and billions of stars of the Milky Way are arranged. Because the solar system is part of the Milky Way, astronomers cannot view it from outside and so had been unable to get a clear understanding of its shape. He identified segments of two spiral arms similar to those observed in the Andromeda Nebula, and also a probable third arm. A Rare Kind of Salute

When the discovery was announced in 1951 at a meeting of the American Astronomical Society, Dr. Morgan received a standing ovation, something rare in scientific proceedings.

"This was the first time that the existence of a spiral pattern was established without question," said Dr. Subrahmanyan Chandrasekhar, a Nobel Prize-winning professor emeritus of astronomy and physics at the University of Chicago. "He was certainly one of the more distinguished astronomers of this century."

One of Dr. Morgan's graduate students who helped in the discovery was Donald E. Osterbrock, who later became director of the Lick Observatory in California. He said Dr. Morgan's research "opened up a lot of new thinking about stellar evolution, star formation and our own star system."

Before his landmark discovery, Dr. Morgan had worked with Philip C. Keenan to develop a system that for the first time allowed astronomers to determine the luminosity of stars directly from observations of their spectra, which are the detailed component colors in the light emitted by stars. He then used the MK (for Morgan Keenan) system to estimate the distances of bright stars within the Milky Way, a major step in discovering the galaxy's spiral structure. These and other techniques were later applied to research on the structure of other galaxies. The Outlook of an Artist

One colleague, Dr. Richard Kron, the current director of the Yerkes Observatory, remarked on an extra-scientific quality, a special way of looking at nature, that probably contributed to Dr. Morgan's successes.

"When he looked at stellar spectra, he thought less in terms of atomic physics and more in terms of artistic patterns," Dr. Kron said. "He constantly referred to his interest in the visual arts as an inspiration for his discoveries in astronomy."

Dr. Morgan was born on Jan. 3, 1906, in Bethesda, Tenn. After attending Washington & Lee University, he graduated with a bachelor's of science degree from the University of Chicago in 1927 and earned his Ph.D. there in 1931 under the guidance of Dr. Otto Struve, one of the foremost astronomers of the early 20th century. He immediately joined the Yerkes staff and began teaching at the university a few years later, becoming a full professor in 1947. He was co-author of "An Atlas of Stellar Spectra," published in 1943 and still widely used by astronomers.

His honors included membership in the National Academy of Sciences, the American Academy of Arts and Sciences and the Pontifical Academy of Sciences. He received the Bruce Gold Medal from the Astronomical Society of the Pacific and the Herschel Medal from the Royal Astronomical Society of London.

Survivors include his wife, Jean; a son, William B., of Rhinelander, Wis.; a daughter, Emily B., of Madison, Wis.; a sister, Sally Selder, and two grandchildren. His first wife, Helen Montgomery Barrett, died in 1963.

Photos: Adapted from "Galaxies," by Timothy Ferris, illustrations by Sarah Landry (Stewart, Tabori & Chang); Artist's rendering of the spiral structure of the Milky Way galaxy discovered by Mr. Morgan; circle at left marks location of the Sun.